That's great, improve it as you can. Taller is better for ease of maintaining too.
I went back and found an easier to read (shorter) version on the perch study that mentions the bike tube....
http://www.yourchickens.co.uk/care-and-advice/the_perfect_perch_1_2842822
You mentioned it's a pipe they're roosting on so it should be easy to wrap the tube around. Maybe use zip ties or ....better yet, use wire at each end to keep it tight.
Chipper
I went back and found an easier to read (shorter) version on the perch study that mentions the bike tube....
http://www.yourchickens.co.uk/care-and-advice/the_perfect_perch_1_2842822
You mentioned it's a pipe they're roosting on so it should be easy to wrap the tube around. Maybe use zip ties or ....better yet, use wire at each end to keep it tight.
Chipper